Presented by Lex Reiter, ETH Zürich
With the concepts for 3D concrete printing established and first demonstrators constructed, robustness, flexibility and productivity become important benchmarks for the applicability of 3D printed concrete in the construction sector. This means, ensuring that concrete can be extruded and stays in place after printing and that components can be constructed seamlessly without process interruptions. To achieve this for substantially high structures means controlling at the same time the yield stress at the time of extrusion and its evolution over time. This is achievable by tailoring rheology and hydration with admixture additions in the extruder, allowing to adjust rheology and structural build-up during printing operation, which besides robustness opens the door for more advanced processing approaches.